[Intel-gfx] [PATCH] drm/i915: properly init lockdep class

[Peter Zijlstra]

On Wed, Dec 13, 2017 at 06:36:33PM +0100, Sebastian Andrzej Siewior wrote:
> +peterz
> context: http://www.spinics.net/lists/intel-gfx/msg149011.html
> 
> On 2017-12-13 17:37:21 [+0200], Joonas Lahtinen wrote:
> > On Wed, 2017-12-13 at 16:06 +0100, Sebastian Andrzej Siewior wrote:
> > > On 2017-12-13 16:00:49 [+0200], Joonas Lahtinen wrote:
> > > > On Thu, 2017-11-30 at 16:19 +0100, Sebastian Andrzej Siewior wrote:
> > > > > The code has an ifdef and uses two functions to either init the bare
> > > > > spinlock or init it and set a lock-class. It is possible to do the same
> > > > > thing without an ifdef.
> > > > > With this patch (in debug case) we first use the "default" lock class
> > > > > which is later overwritten to the supplied one. Without lockdep the set
> > > > > name/class function vanishes.
> …
> > > > At least according to the source there doesn't seem to be clarity about
> > > > what is the right thing to do, this being just one option.

The proposed patch is definitely the right thing to do. The fact that it
doesn't require #ifdef is a very big clue.